Means for holding film flat in roll-film cameras



Aug. ll, 1931. J. CHRISTIE 51,817,965

MEANS FOR HOLDING FILI FLAT IN ROLL FILI CAIERAS Filed nay s1. 1930 y Patented Aug. 11, 1931 i UNITED. s'1'.tf'i'v'l-ISl PATENT- OFFICE com cnmsrm, oF nocnEsrEn, NEW Yonx, ASSIGNOR To EAs'rMnn Konan CoM-i PANY, or ROCHESTER, New Yonx, A coRroRA'rIoN oF NEW Yonx i MEANS FOB HOLDING FILM FLAT IN ROLL-FILM CAMERAS i Application ylell lay 31, 1930.' Serial No.` 458,265.

My present invention relates to photography and more particularly to filmtpressure plates or ads, employed to hold ke light sensitive lm flat 1n the focal plane of a 5 photographic camera. c.

AAn object of the present invention is to provide a film ressure plate which is efficient, and simpe in operation andat the same time may be manufactured at a low` proper position with relation to thefcamerav at ,all times. To these and other ends the y invention resides yin certain improvements and combination of arts all as Will be hereinafter more fully escribed, the novel 'fea- 4endof the specification.

Y This film pressure plate is designed more fiafli'ticularly to be employed in photographic to Underwood and Reynolds No. 1,918,135, issued March 6, 1917, y

In the drawings wherein like reference characters indicate like parts throughout,

isclosing a plan view of the film' pressure rplate located in said casing, the film ,y and film spools being shown in broken lines;

Fig. 2 is a cross section of a cam'era casing disclosing an elevation of kthe film pressure plate located in the casing, the camera body and exposure frame,`shown in broken lines, being partially inserted in s'aidgcass t n lzulig. 3 is aperspective of the film pressure Eig. 4 is an elevation of a film supplyroll and one endof the Vlin pressurevrp ate, the nenn vange of saidroll being removed, and

s es@ .s a esmas..

tures being pointed, out in the claims at they camerasfof the type disclosed 1n the patent` Fi 1 is a cross section of a camera casthe center thereof, and therefore slightuniversal movement'of the vp atek relaof the pressure plate and exposure frame. Referring more particularly tojthedrawings, 1 indicates t e camera casing the film supply spool chamber.; 3the film takeup spool chamber; 4 the winding key; B the camera body having anexposure frame 5 adapted to, be placed intermediate the spool;

chambers; and 6 the film pressure plate',y

In the ends of the spool chambers are located mounts for the spools such kasthey block 7 and the'spring 8 at the supplyendv 2 yand blocks 7 at the takeup end 3. These mounts limit the lateral movement `of the filmv spools 9 and 10 and limit' the move-` ment of the pressure plate in an outward diy rection as will be pointed outlater. To further locate the spools in their chambers, thecamera body rB is prOvidedwithsupport rollers 11 withk which the spool flanges contact to reduce friction and prohibit the."

spools from longitudinal movement with respect to the camera casing; `Rollers l2 are to protect the film 13 from scratchingand.

aid itinv smooth passage from one spool to the other.

The film pressure plate is. provided to maintain the film 13 fiat in thefocal plane `of the .camera immediately behind the ex` posurewindow 14 in--the exposure frame 5. It comprises a flat metal plate having two sprin s l5 struck from the centerk thereof; fourk ugsl, one in each corner; two small apertures 17, one in each of two opposite.'

corners; two side rails 18 struck up alongl the edges; a Ysmall window 19 ythroug which the exposure numbers on thefilm backing paper can be seen; and a tongue 20 extendlng fromone end thereof.

kvThe springs 15 contact with the back of the casing land yieldingly press thejplatev 6 up a ainst the exposure frame 5. It shouldenotedv that these springs contact with a portion of the camera casing y1 near yermit a tivel to the camera casin kW en the camera body isremoved the' plate 6 is -still retained in a de ressed position b ythe corner lugs 16 w ich contact with tieblocks 7 and the spring' 8. The

outward movement of the plate G is so limited to permit the easy removal of the film spools 9 and 10 from their respective chambers 2 and 3. If said plate 6 was allowed to spring outwardly, upon the removal of the camera body B, it would block the passage of' the film spools from their chambers and cause an inexperienced operator a good deal of trouble in loading and unloading his camera.

The apertures 17 are provided to have a sliding engagement with the rivets Q1 which hold the plate 6 in the proper position with relation to the casing 1. The apertures 17 are of such size that the plate may turn as Well as slide upon said rivets 21 to allow the slight universal movement of said plate 6 mentioned above. Then in contact with the exposure frame 5, as shown in Fig. 5, the side rails 18 form a channel for the fiim 13 and the backing paper 22 to pass through thereby keeping the film fiat in the focal plane of the camera without actual pressure on said film 13 which would tend to scratch f or mar the film through undue pressure through the film backing paper 22.

IVhen spooling the lm 1B some of the manufacturers provide a fold 23 in the backing paper 22, as shown in Fig. e, which prevents the paper 22 from tightening and tearing or from buckling the film when being wound. This fold 23, though eliminating one difficulty, sometimes causes another by catching over the end of the pressure plate of pad in general use today, tearing or wrinkling the paper and causing difficulty in winding. Therefore I provide a lip which projects from one end of my pressure plate 6 under the supply spool 9 so that the fold 23 cannot come in contact with the edge of plate and will pass on through the winding operation smoothly.

rlhe advantages of my pressure plate can easily be seen as it is simple and efficient in construction and operation, and may be manufactured at an extremely low cost.

IVhile I have shown the prefered embodiment of my invention in the accompanying drawings, it will be understood, of course, that such embodiment may be changed and varied by the exercise of mechanical skill and judgment without departing from the spirit of the invention as defined in the appended claims:

IVhat I claim as new and desire to secure by Letters Patent is:

1. In a roll film camera, the combination with an exposure frame, of means for holdw ing a film fiat thereagainst including a pres sure plate comprising a fiat plate, springs carried by thel plate adapted to press said plate against said exposure frame, raised edges on the plate adapted to limit the movement of the plate toward the frame and cooperating parts on the camera and plate Lslzees for limiting the movement of the plate relative to the camera.

2. In a roll film camera, the combination with an exposure frame, of means for holding a film flat thereagainst including a pressure plate comprising a flat plate, springs arried by the plate adapted to press said plate against said exposure frame, raised edges on the plate adapted to limit the movement of the plate toward the frame and coope ating parts on the camera and plate for limiting the movement of the plate relative to the camera, comprising apertures in said plate having loose engagement with coinciding rivers secured to said camera.

3. In a roll film camera, the combination vith an exposure frame, ot means for holding a film fiatthereagainst including a pressure plate comprising a flat plate, springs carried by the plate adapted to press said plate against said exposure frame, raised edges on the plate adapted to limit the movement of the plate toward the frame and cooperatingr parts on the camera and plate for limiting the movement of the plate relative to the camera comprising lugs located on said plate which contact against blocks positioned in said camera.

el. In a roll film camera, the combination with an exposure frame, of means for holding a film fiat tlicreagainst including a pressure plate comprising a flat plate, springs carried by the raised edges on the plate adapted to limit the movement of the plate toward the frame and cooperating parts on the camera and plate for limiting the movement of the plate relative to the camera, comprising apertures in said plate having loose engagement with coinciding rivets cured to said camera, and lugs projecting from said plate which contact against blocks positioned in said camera.

5. In a roll film camera, the combination with an exposure frame, of means for holding a film flat thereagainst including a pressure plate comprising a. flat plate, springs carried by the plate adapted to press said plate against said exposure frame, raised edges on the plate adapted to limit the movement of the plate toward the frame and cooperating parts on the camera and plate for limiting the movement of the plate relative to the came a, and a tongue extendw ing from one end of said plate past the eenter and in back of the film supply spool carried by the camera.

6. In a roll film camera, the combination with an exposure frame, of means for hold ing a film fiat thereagainst including a pressure plate comprising a flat plate, springs carried by the plate adapted to press said plate against said exposure frame, raised edges on the plate adapted to limit the movement of the plate toward the frame and cooperating'parts on the camera and' plate for ner/,ees

limiting the movement of the plate relative l tact against blocks positioned in said camera and a tongue extending from one end o sid plate past the center and in back of the film supply spool carried by 'the camera.

7. In a roll film camera, the combination with an exposure frame, of means for holding a ilm flat thereagainst including apressure plate comprising ailat plate having springs struck t erefrom, and pro'ecting toward the center thereof, adapte to press said late a ainst said exposure frame andv simu taneous y permit said plate a slight yuniversal movement.

8. In a roll holding camera, the combination with a sipply spool and a take-up spool chambers an an exposure frameyintermediste said chambers, of a means for holding a film flat against said exposurey frame includin a pressure plate, s ring pressed toward t eexposure frame, xaving a tongue projecting from the end of said pressure plate adjacent the supply spool chamber.

9. In a roll holding camera, the combination with a su ply spool and a take-up spool chambers an an exposure frame intermemedate said chambers, of a means lfor holding a film Hat against said exposure frame including a pressure plate, spring pressed toward the exposure frame, having a tongue projecting from the end of said pressure plate adjacent the supply spool c am-y ber, said tongue extending into the spool chamber behind and ast the center of a spool positioned in sai s ool chamber.

Signed at Rochester, ew York this 29th day of May, 1930.

' JOHN CHRISTIE. 

